# code: http://golf.shinh.org/reveal.rb?Set+symmetric+difference/tails_1643205712&nbb
# target Nibbles version: 0.25
# commenter version: 0.1.2.181

* #(join):[[chr],[chr]] 
    " " #(string):[chr] 
    %~ #(split by):[[[chr]],[[chr]]] 
        `^ #(list xor):[[chr]] 
            % #(split (remove empties)):[[chr]] 
                @ #(= fstLine):[chr] 
                ~ #(auto = words):auto 
            + #(concat):[chr] <--arg( A:[chr] ) 
                ;_ #(= allLines):[[chr]] 
        , #(length):int <--arg( B:[chr] ) 
            #(implicit arg = B):[chr]